1. Field of the Invention
The present invention relates to network devices and a method of controlling the network devices, and more particularly to network devices and a method of controlling them which are suitable for building a control system in which network devices connected to an identical network, and network devices connected to different networks through gateways coexist.
2. Description of the Prior Art
With widespread use of PC and broadband communication networks such as ADSL (Asymmetric Digital Subscriber Line), access to the Internet from home is further increasing. In AV devices, the HAVi standards are defined as a middleware for interoperability of devices connected through the IEEE1394 serial interface (hereinafter referred to as 1394IF), and AV/C (Audio Video Control) commands are defined. Also, the ECHONET standards are defined as network standards for so-called home appliances such as air conditioner and refrigerator. Furthermore, some AV devices and home appliances that are connectable with an IP network are emerging, and device scan be controlled through the Internet.